the screaming Jets

Getting ready to do some more jetting.
I haven't got the CH temperature above 230 while commuting, and it feels like the low end is getting richer. I will check whether the screws are working their way out (air and idle) or whether the air filter is getting clogged with 2t oil from the excessive blowback.
I have pretty much ignored the main jet for the last month as I have only been commuting, but I will ...
1) clean out the filter pod and see how the bike runs tomorrow.
2) count out the turns on the air and idle screws and check they are staying the same after a week.
3) put in a smaller main jet and see if there's a performance increase.
4) put the timing back to 18 BTDC and check with light.
5) change the needle to a leaner taper (3/8 throttle- WOT)

results...
1) I cleaned out the foam air filter pod with soapy water and lightly oiled it with filter oil. I forgot I did this and when I started the scooter up this morning I thought I had a jammed throttle. It ran like a dream al the way to work (apart from the headlight falling out and hanging like a horror movie eyeball). I guess that cancels 2,4 and 5. I still need to sort out the main jet.